Screw-plate



(No Model.) A. M. DELLINGER.

Patented oat. 1, 1895.

SCREW PLATE.

Ni'rnn States ATENT FFICEG SCREW-PLATE.

SPECIFICATION forming part of Letters Patent No. 547,245, dated October 1, 1895.

Application filed October 1, 1894.

To all whom it may concern.-

Be it known that I, ABRAHAM M. DELLIN- GER, a citizen of the United States ofAmerica, residing at Lancaster, in the county. of Lancaster and State of Pennsylvania, have invented new and useful Improvements in Screw- Plates, of which the following is a specification.

This invention relates to screw-plates, the object being to provide an improved plate of this description for holding and manipulating several screw-cutting tools; and the invention consists in the novel construction and arrangement of the various parts of the device, all as hereinafter fully described, and more particularly pointed out in the claim.

In the drawings forming part ofthis specification, Figure 1 is a perspective view of a screw-plate constructed according to my improvements, said view illustrating chasers adapted to be used therewith. Fig. 2 is a perspective view of a portion of the screw plate and parts thereto attached, illustrating a modification of the construction of Fig. 1 in respect to means for adjusting and holding the chasers. Fig. 3 is a perspective view of one of the chasers.

In the drawings, A indicates the screwplate provided with the tubular arms K, in which are placed any convenient handles to serve in turning the plate in the operation of cutting screws on bolts, rods, pipe, or other articles.

The plate A is provided with two rigidlyfixed triangular abutments A on its face, preferably integral therewith, as shown, located opposite each other. The inner ends of said abutments adjoining the center of the screw-plate have each, preferably, the form of a segment of a circle. The opposite inwardly-convergent edges or faces of said abutments A which are vertical to the upper side of the plate therebetween, are finished to suitably receive against said edges a thread-cutting tool or chaser D, one end of which is suitably formed for this purpose, as shown. Each of said chasers is preferably made from a piece of a flat steel bar and has a recess 8 formed in one side, at one end of which is an abutment a, that is in a plane oblique to the side of the chaser in which said recess is formed. Means for rigidly se- Serial No. 2 4,6532- (No model.)

curing said chasers D in operative position on the screw-plate and for adjusting them endwise for threading articles of varying diameters and to take up for wear of the threadcutting end of the chaser are provided, and they consist of clamp-blocks B, which have the form of a segment of a circle, located between the abutments A and having, preferably, overhanging fianges c thereon. Said blocks have each a bolt hole vertically through it, through which loosely passes a bolt 3, which screws into the plate A, and said bolt holds the block firmly on the latter. The oblong bolt-hole permits of the move ment of the block tightly against the chasers D before tightening said bolt. flanges c on blocks B engage with the upper edges of the chasers and hold them from rising up from the face of the plate A when operated for threading. Said bolts 8 provide, ordinarily, ample security against any backward movement of the clamp-blocks B induced by the strain upon the chasers D after said blocks have been forced against the latter and while screw-threads are being cut, whereby the chasers may become loosened and be not held firmly up to the work; but to provide against any possibility of, a rearward movement of .said clamp-blocks under the conditions just stated the bolts 5, operating in suitable bosses or standards 4.- on the face of the plate A, are provided. Said bolts 5 also serve to aid in crowding the clampblocks against said chasers.

The part it on the under side of the plate A is the usual tubular guide for tools of this class, whereby the cutting-edges of the chasers are caused to assume positions parallel to the surface of a rod or tube being operated upon, and thus insure the formation of a screwthread having a surface in a plane with that of the article on which it is formed.

It preferred, the chaser-adj usting construction shown in Fig. 2 may be substituted for that above described, in which screw 7 engages in a recess in the side of the chaser. The said alternative construction of Fig. 2 embodies an arm E, extending from the edge of the screw-plate A, having a part thereon opposite the outer end of the chaser D, through which a screw-bolt 6 operates directly against the outer end of said chaser The said for holding and adjusting the chaser in suheach edge to catch over the top edge of the I5 stantially the same manner and for the same I chasers; screws for adjusting the pressure of purpose as does the said screw 7. The means the blocks on the chase-rs, and screws for sefor employing the latter, however, for adj ustcuring the blocks adjustably to the plate or 5 ing and holding the chasers are less cumberbody; the chasers placed between the abutsome and costly than those illustrated in ments and the blocks, and provided with the 20 Fig. 2. shouldered. recesses z, and the screws 7 for What Iclaim as my invention isengaging with said shoulders and preventing The screw plate or body having a central any backward movement of the chasers, sub- 10 aperture, and provided upon its top with the stantially as described.

two abutments, having converging edges; ABRAHAM M. DELLINGER. combined with the clamp blocks of greater Witnesses:

height than the abutments, and provided H. D. SAOKETT,

with two converging edges, and a flange on CHAS. E. LONG. 

